Drying cylinder

ABSTRACT

A drying cylinder in which the inside of the mantle or at least its end portions have circumferential grooves for collecting condensate. The inlet of a condensate drain pipe is placed in each groove and the pipes have been joined to a common condensate collecting pipe having adjustment means for regulating the amount of condensate from the drain pipes. The condensate collecting pipe is further connected to a condensate draining system of the cylinder.

United States Patent Nykopp [151 3,659,349 51 'May 2,1972

[ DRYING CYLINDER [72] Inventor: Erik A. Nykopp, Tampere, Finland [73]Assignee: Oy-Tampella Ab, Tampere, Finland [22] Filed: Nov. 26, 1969 211App]. No.2 880,345

[52] U.S. Cl ..34/l24, l37/625.41 [51] Int. Cl ..F26b 11/02 [58] FieldofSearch ..34/124, 125, 119; 165/159, 165/174, 87, 92, 124, 125;137/625-641; 251/123, 209

[56] References Cited UNITED STATES PATENTS 1,715,677 6/1929 Ritchie..34/125 2,384,078 9/1945 Curtis ..251/209 3,299,531 8/1964 Kutchera eta1. .....34/125 267,666 11/1882 Brigham ..34/125 1,594,718 8/1926 Fulton"34/124 3,047,274 7/1962 Wilson ..165/174 FOREIGN PATENTS ORAPPLICATIONS 839,761 6/ 1960 Great Britain ..251/209 PrimaryExaminer-Charles Sukalo Assistant Examiner-Theophil W. StreuleAttorney-Roylance, Abrams, Kruger, Berdo & Kaul ABSTRACT A dryingcylinder in which the inside of the mantle or at least its end portionshave circumferential grooves for collecting condensate. The inlet of acondensate drain pipe is placed in each groove and the pipes have beenjoined to a common condensate collecting pipe having adjustment meansfor regulating the amount of condensate from the drain pipes. Thecondensate collecting pipe is further connected to a condensate drainingsystem of the cylinder.

3 Claims, 2 Drawing Figures PATENTEDHAY 2|972 SHEET NF 2 3,659,349

PAIENTEUMM 2 I972 3,659,349 SHEET 2 BF 2 Fig. 2

DRYING CYLINDER BACKGROUND OF THE INVENTION several condensate drains.However, it has been found that e.g. a paper web in its passage throughthe drying section of a paper machine, which consists of severalcylinders of the said kind, usually dries at faster rate on its marginsthan in the center. Endeavours have therefore been made to retard thedrying of said marginal parts and to improve the drying of the centralparts of the web. In attempts to render the drying more efficient in thecentral parts of the web, for instance, air has been blown into thepockets in the dryer section of the paper machine, directing the airflow particularly towards the central parts of the paper web. However,this is a cumbersome solution; it requires a blower for each pocket, inaddition to which the system has to be monitored continuously.

SUMMARY OF THE INVENTION In accordance with this invention each grooveis provided with a vertical condensate drain pipe having its lower endin the groove. The upper end of the condensate drain pipes emerges intoa condensate collecting pipe connected to a condensate draining systemof the cylinder for withdrawing condensate from the grooves. There isalso means for regulating the quantity of condensate withdrawn througheach condensate drain pipe.

The regulating means may be a turnable tube inside the condensatecollecting pipe and provided with oblique cuts for opening and closingthe drain pipe openings into the collecting The advantage of theinvention is that the surface temperature of the drying cylinder in itsmarginal part can be regulated.

BRIEF DESCRIPTION OFTHEDRAWINGS FIG. 1 presents, partly in axialsection, a drying cylinder fitted with an arrangement according to theinvention, and

FIG. 2 shows on enlarged scale the marginal part of the drying cylinder,with its grooves and condensate draining system.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the drawings, the referencenumeral 1 indicates the mantle of the drying cylinder, 2 and 3 are endplates integrally fixed to the mantle, and 4 and 5 are axle pinsprojecting from the end plates. Through the axle pin 4, steam isconducted into the drying cylinder along the steam pipe 6, which hassteam distribution apertures 7 at both ends. Enclosed inside the steampipe 6 runs the condensate drain pipe 8, from which three branch pipes9, 10 and 11 branch off and which pass through the wall of the steampipe 6; of these, the pipe indicated by reference numeral 10 has beenconnected to a prior known device 12, which removes condensate from theinterior surface of the drying cylinder mantle 1, The condensate drainpipe 8 and the branch pipes 9, 10 and 11 constitute the condensatedraining system of the cylinder.

The branch pipes 9 and 11 have been connected to a condensate draineraccording to the present invention, including condensate collectinggrooves 13 provided in the marginal parts of the mantle 1 and which runcircumferentially to the mantle, of which grooves there are six in eachend portion of the cylinder in the embodiment illustrated by thedrawing.

When condensate accumulates in these grooves, it delays the 1 transferof heat from inside the cylinder to the outer surface of its mantle,thus retarding the drying of the paper web in contact with the outermantle surface opposite to the grooves. It is obvious that the rate ofheat transfer is inversely proportional to the amount of condensate inthe grooves; it follows that the heat transfer into the paper web whichis being dried can be separately adjusted opposite each groove, asdesired, by adjusting the amount of condensate present in each groove.For this reason, the branch pipes 9 and 11 of the condensate drainingsystem have been angulated to pass over the grooves 13 and fixed to theend plates 2 and 3, respectively. Since the design is identical for bothbranch pipes, it shall only be described with reference to the branchpipe 9, which has been depicted in FIG. 2.

From the branch pipe 9, a condensate drain pipe 14 has been carriedclose to the bottom of each groove 13. Within the part 15 hereaftercalled the common condensate collecting pipe of the branch pipe 9 lyingabove the grooves 13 another, adjustment tube 16 has been fitted, whichhas been provided with at least one oblique cut 17. When the adjustmenttube 16 is turned by the nut 18 fixed to its end piercing the endplate-2, the ports of the condensate drain pipes 14 opening into thecommon condensate collecting pipe 15 can be gradually closed in sequencefrom the outer rim towards the central part of the cylinder until allports have been closed. When the nut 18 is turned in opposite direction,the pipes 14 will be opened in inverted sequence. In the event that inthe adjustment tube 16 two oblique cuts have been provided which form anangle with each other and both deviate from the axial direction of thetube, two different adjustment schedules are possible. It is to beunderstood that the number of such oblique cuts may even be greater thantwo, but their number is mostly restricted to two, owing to excessiveweakening of the wall of the adjustment tube with increasing number ofoblique cuts.

It is thus possible, with the aid of the adjustment tube 16, to make theamount of condensate present in the grooves 13, for instance, todecrease from'the margin of the mantle towards its central part, or viceversa.

It is obvious that, in order to enable the adjustment to be made alsoduring operation, the mechanism serving to turn the adjustment tube 16may also be made remote-controlled; this being a technical arrangementwhich can be solved by any person skilled in the field in numerous ways,and since it does not constitute the actual object of the presentinvention, no more detailed description of it shall be presented in thisconnection.

The adjustment tube may also be provided with perforation at appropriatespacing, the adjustment being accomplished by moving this tube axially.

What is claimed is:

1. In a drying cylinder, said cylinder having:

a plurality of circumferential condensate collection grooves on theinner surface of the mantle of said cylinder;

a plurality of condensate removing means inside said cylinder, eachcondensate removing means having an inlet and an outlet, each said inletcommunicating with a groove;

a common condensate collection means communicating with each outlet ofsaid condensate removing means; and

an outlet control means disposed within said common condensatecollection means for separately controlling the amount of condensatepassing through each respective outlet.

2. The drying cylinder as defined in claim 1 wherein said outlet controlmeans comprises a turnable adjustment means disposed within said commoncondensate collection means.

3. The drying cylinder as defined in claim 1 wherein said commoncondensate collection means is cylindrically shaped and said outletcontrol means comprises a turnable cylinder disposed within saidcollection means, said turnable cylinder having an oblique cuttherethrough.

1. In a drying cylinder, said cylinder having: a plurality ofcircumferential condensate collection grooves on the inner surface ofthe mantle of said cylinder; a plurality of condensate removing meansinside said cylinder, each condensate removing means having an inlet andan outlet, eacH said inlet communicating with a groove; a commoncondensate collection means communicating with each outlet of saidcondensate removing means; and an outlet control means disposed withinsaid common condensate collection means for separately controlling theamount of condensate passing through each respective outlet.
 2. Thedrying cylinder as defined in claim 1 wherein said outlet control meanscomprises a turnable adjustment means disposed within said commoncondensate collection means.
 3. The drying cylinder as defined in claim1 wherein said common condensate collection means is cylindricallyshaped and said outlet control means comprises a turnable cylinderdisposed within said collection means, said turnable cylinder having anoblique cut therethrough.